It’s hard to describe why the Daleks were so terrifying. They were just metal boxes spinning round threatening to ‘exterminate’ people. But somehow it worked. Somehow they managed to impregnate the national consciousness and became the most terrifying symbol of destruction. Maybe it was the weird staccato voice. Maybe it was a fear of the Nazis on which they were apparently based. But whatever the reason, they were frightening enough to give most children nightmares in the 1960s.